samedi 23 juillet 2016

We are now attempting the last leg of the round-the-world solar flight. Don’t miss out. Bertrand Piccard took off from Cairo, Egypt at 11:28PM UTC on July 23rd and 1:28AM CEST, 7:28PM EDT on July 24th. It hasn’t been easy for the mission engineers to find a favorable window and it’s looking like a real exploration flight ahead, as we are facing new flight conditions: extreme heat, updrafts and downdrafts.

Solar Impulse Airplane - Bertrand Piccard's takeoff from Cairo

Don’t miss your chance to witness this flight! If you have previously postponed watching one of these flights, this is your last chance! We have prepared an entire live experience for you with a TV show including important interviews, essential information, and a virtual cockpit where you can follow the flight path, energy level, pilot’s vitals, all on http://solarimpulse.com.

vendredi 22 juillet 2016

Forty years ago, NASA's Viking mission made history when it became the first mission to successfully land a fully operational spacecraft on Mars. This mission gave us our first real look at the Martian surface, as well as the fundamental science that has enabled continued missions to the Red Planet, laying the foundation for NASA’s Journey to Mars.

The spacecraft, dubbed Viking 1, touched down on the Martian surface July 20, 1976 — its counterpart, Viking 2, followed suit and landed September 3 of that same year.

The mission objectives were carefully laid out: Obtain high-resolution images of the Martian surface, characterize the composition of the Martian surface and its atmosphere, and search for life.

After years of imaging, measuring and experimenting, the Viking spacecraft ended communication with the team on Earth, leaving behind a multitude of data that scientists would study for the next several years.

As engineers and scientists planned for later missions to Mars, the rolls of microfilm containing the Viking data were stored away for safekeeping and potential later use. It would be another 20 years before someone looked at some of these data again.

NASA's Deep Archives

Image above: Data from the Viking biology experiments, which is stored on microfilm, has to be accessed using a microfilm reader. David Williams and the archive team are working to digitize the data to make it more accessible. Image Credits: David Williams.

David Williams is the planetary curation scientist for the NASA Space Science Data Coordinated Archive at Goddard Space Flight Center in Greenbelt, Maryland. The archive houses much of NASA's planetary and lunar spacecraft data stored on microfilm and computer tapes, including the Viking data. Williams works to digitize all of the data so that it can be easily accessed from the web.

"At one time, microfilm was the archive thing of the future," Williams said. "But people quickly turned to digitizing data when the web came to be. So now we are going through the microfilm and scanning every frame into our computer database so that anyone can access it online."

In the early 2000s, Williams received a call from Joseph Miller, professor of pharmacology at the American University of the Caribbean School of Medicine, requesting data from the Viking biology experiments. But all that was left of the data was stored on microfilm.

"I remember getting to hold the microfilm in my hand for the first time and thinking, 'We did this incredible experiment and this is it, this is all that's left,'" Williams said. "If something were to happen to it, we would lose it forever. I couldn't just give someone the microfilm to borrow because that's all there was."

Image above: The results of the Viking biology experiments might have been controversial, but the mission helped paved the way for later missions to Mars.Image Credits: David Williams.

The archive team decided to tear open the boxes of microfilm and begin digitizing the data.

Lasting Knowledge

Miller wanted to analyze the data from Viking's biology experiments to see if the Viking science team had missed something in the original analysis. He concluded that one of the Viking biology experiments did, indeed, offer proof that life may exist on Mars.

In one of the experiments, known as Labeled Release (LR), the Viking landers scooped up soil samples and applied a nutrient cocktail. If microbes were present in the soil, they would likely metabolize the nutrient and release carbon dioxide or methane. The experiment did indicate metabolism, but the other two Viking experiments did not find any organic molecules in the soil. The science team believed the LR data had been skewed by a non-biological property of Martian soil, resulting in a false positive. While arguments continue, this remains the consensus view.

This was not the first time scientists disagreed about the results of the Viking biology experiments. Since the very first data analysis, scientists argued about whether the experiments proved that Mars really was harboring life.

"The data were very controversial," Williams said. "But, in a way, it helped push for continued Mars missions and landers. The very next missions were planned around what we found with Viking, and then the next group of missions built upon those. But even our most current Mars missions still refer back to Viking."

One such mission is Curiosity, which landed on Mars August 6, 2012. Equipped with an instrument suite known as Sample Analysis at Mars (SAM), the Curiosity rover is capable of searching for organic compounds on the Martian surface. SAM is able to detect a lower concentration of a wider variety of organic molecules than any other instrument sent to Mars, including those on Viking.

"We built SAM based on a lot of experience and heritage from Viking," said Danny Glavin, associate director for Strategic Science in the Solar System Exploration Division at NASA Goddard and former planetary protection lead for SAM. "The capabilities of the Viking landers and instruments were very advanced for the technology at the time. Just demonstrating that you could land a spacecraft on the Martian surface successfully was a huge feat."

Unlike Viking at the time, data from Curiosity's experiments are uploaded to the Planetary Data System for easy accessibility.

"Viking data are still being utilized 40 years later," Glavin said. "I know the same will be true for SAM. The point is for the community to have access to this data so that scientists 50 years from now can go back and look at it."

Sunset at the Viking Lander 1 Site

Image above: On July 20, 1976, at 8:12 a.m. EDT, NASA received the signal that the Viking Lander 1 successfully reached the Martian surface. This major milestone represented the first time the United States successfully landed a vehicle on the surface of Mars, collecting an overwhelming amount of data that would soon be used in future NASA missions. Upon touchdown, Viking 1 took its first picture of the dusty and rocky surface and relayed the historic image back to Earthlings eagerly awaiting its arrival. Viking 1, and later Viking Orbiter 2, collected an abundance of high-resolution imagery and scientific data, blazing a trail that will one day take humans to Mars. Image Credits: NASA/JPL.

This color image of the Martian surface in the Chryse area was taken by Viking Lander 1, looking southwest, about 15 minutes before sunset on the evening of Aug. 21. The sun is at an elevation angle of 3 or 4 degrees above the horizon and about 50 degrees clockwise from the right edge of the frame. Local topographic features are accentuated by the low lighting angle. A depression is seen near the center of the picture, just above the Lander’s leg support structure, which was not evident in previous pictures taken at higher sun angles. Just beyond the depression are large rocks about 30 centimeters (1 foot) across. The diffuse shadows are due to the sunlight that has been scattered by the dusty Martian atmosphere as a result of the long path length from the setting sun. Toward the horizon, several bright patches of bare bedrock are revealed.

In 2016, the Viking legacy continues. Lessons learned from Viking technology blazed the trail for future Mars missions, which have vastly improved our understanding of the Red Planet. Today NASA has a fleet of orbiters and rovers on and around Mars, making key discoveries such as evidence of liquid water near the surface of Mars and paving the way for future human-crew missions. The Mars 2020 rover recently passed an important mission milestone toward launch in 2020, arriving on Mars in February of 2021. Its mission is to seek signs of past life and demonstrate new technologies to help astronauts survive on Mars, with the goal of sending humans to the Red Planet in the 2030s.

Solar material repeatedly bursts from the sun in this close-up captured on July 9-10, 2016, by NASA’s Solar Dynamics Observatory, or SDO. The sun is composed of plasma, a gas in which the negative electrons move freely around the positive ions, forming a powerful mix of charged particles. Each burst of plasma licks out from the surface only to withdraw back into the active region – a dance commanded by complex magnetic forces above the sun. SDO captured this video in wavelengths of extreme ultraviolet light, which are typically invisible to our eyes. The imagery is colorized here in red for easy viewing.

jeudi 21 juillet 2016

NASA's Mars rover Curiosity is now selecting rock targets for its laser spectrometer -- the first time autonomous target selection is available for an instrument of this kind on any robotic planetary mission.

Using software developed at NASA's Jet Propulsion Laboratory, Pasadena, California, Curiosity is now frequently choosing multiple targets per week for a laser and a telescopic camera that are parts of the rover's Chemistry and Camera (ChemCam) instrument. Most ChemCam targets are still selected by scientists discussing rocks or soil seen in images the rover has sent to Earth, but the autonomous targeting adds a new capability.

During Curiosity's nearly four years on Mars, ChemCam has inspected multiple points on more than 1,400 targets by detecting the color spectrum of plasmas generated when laser pulses zap a target -- more than 350,000 total laser shots at about 10,000 points in all. ChemCam's spectrometers record the wavelengths seen through a telescope while the laser is firing. This information enables scientists to identify the chemical compositions of the targets. Through the same telescope, the instrument takes images that are of the highest resolution available from the rover’s mast.

Image above: NASA's Curiosity Mars rover autonomously selects some targets for the laser and telescopic camera of its ChemCam instrument. For example, on-board software analyzed the Navcam image at left, chose the target indicated with a yellow dot, and pointed ChemCam for laser shots and the image at right. Image Credits: NASA/JPL-Caltech/LANL/CNES/IRAP/LPGNantes/CNRS/IAS.

AEGIS software, for Autonomous Exploration for Gathering Increased Science, had previously been used on NASA's Mars Exploration Rover Opportunity, though less frequently and for a different type of instrument. That rover uses the software to analyze images from a wide-angle camera as the basis for autonomously selecting rocks to photograph with a narrower-angle camera. Development work on AEGIS won a NASA Software of the Year Award in 2011.

"This autonomy is particularly useful at times when getting the science team in the loop is difficult or impossible -- in the middle of a long drive, perhaps, or when the schedules of Earth, Mars and spacecraft activities lead to delays in sharing information between the planets," said robotics engineer Tara Estlin, the leader of AEGIS development at JPL.

The most frequent application of AEGIS uses onboard computer analysis of images from Curiosity's stereo Navigation Camera (Navcam), which are taken routinely at each location where the rover ends a drive. AEGIS selects a target and directs ChemCam pointing, typically before the Navcam images are transmitted to Earth. This gives the team an extra jump in assessing the rover's latest surroundings and planning operations for upcoming days.

To select a target autonomously, the software's analysis of images uses adjustable criteria specified by scientists, such as identifying rocks based on their size or brightness. The criteria can be changed depending on the rover’s surroundings and the scientific goals of the measurements.

Another AEGIS mode starts with images from ChemCam's own Remote Micro-Imager, rather than the Navcam, and uses image analysis to hone pointing of the laser at fine-scale targets chosen in advance by scientists. For example, scientists might select a threadlike vein or a small concretion in a rock, based on images received on Earth. AEGIS then controls the laser sharpshooting.

"Due to their small size and other pointing challenges, hitting these targets accurately with the laser has often required the rover to stay in place while ground operators fine tune pointing parameters," Estlin said. "AEGIS enables these targets to be hit on the first try by automatically identifying them and calculating a pointing that will center a ChemCam measurement on the target."

From the top of Curiosity's mast, the instrument can analyze the composition of a rock or soil target from up to about 23 feet (7 meters) away.

Image above: This May 11, 2016, self-portrait of NASA's Curiosity Mars rover shows the vehicle at the "Okoruso" drilling site on lower Mount Sharp's "Naukluft Plateau." The scene is a mosaic of multiple images taken with the arm-mounted Mars Hands Lens Imager (MAHLI). Image Credits: NASA/JPL-Caltech/MSSS.

"AEGIS brings an extra opportunity to use ChemCam, to do more, when the interaction with scientists is limited," said ChemCam Science Operation Lead Olivier Gasnault, at the Research Institute in Astrophysics and Planetology (IRAP), of France's National Center for Scientific Research (CNRS) and the University of Toulouse, France. "It does not replace an existing mode, but complements it."

The U.S. Department of Energy's Los Alamos National Laboratory in New Mexico leads the U.S. and French team that jointly developed and operates ChemCam. IRAP is a co-developer and shares operation of the instrument with France's national space agency (CNES), NASA and Los Alamos.

The Curiosity mission is using ChemCam and other instruments on the rover as the vehicle investigates geological layers on lower Mount Sharp. The rover's extended mission is analyzing evidence about how the environment in this part of Mars changed billions of years ago from conditions well suited to microbial life -- if life ever existed on Mars -- to dry, inhospitable conditions. For more information about Curiosity, visit: http://mars.jpl.nasa.gov/msl

Celebrating its 50th anniversary this year, the TV series "Star Trek" has captured the public’s imagination with the signature phrase, "To boldly go where no one has gone before." NASA's Hubble Space Telescope doesn't "boldly go" deep into space, but it is "boldly peering" deeper into the universe than ever before to explore the warping of space and time and uncover some of the farthest objects ever seen.

When "Star Trek" was first broadcast in 1966, the largest telescopes on Earth could only see about halfway across the universe - the rest was uncharted territory. But Hubble's powerful vision has carried us into the true "final frontier."

This is epitomized in the latest Hubble image released today in time for the new motion picture "Star Trek Beyond." The Hubble image unveils a very cluttered-looking universe filled with galaxies near and far. Some are distorted like a funhouse mirror through a warping-of-space phenomenon first predicted by Einstein a century ago.

In the center of the image is the immense galaxy cluster Abell S1063, located 4 billion light-years away, and surrounded by magnified images of galaxies much farther.

Thanks to Hubble's exquisite sharpness, the photo unveils the effect of space warping due to gravity. The huge mass of the cluster distorts and magnifies the light from galaxies that lie far behind it due to an effect called gravitational lensing. This phenomenon allows Hubble to see galaxies that would otherwise be too small and faint to observe. This "warp field" makes it possible to get a peek at the very first generation of galaxies. Already, an infant galaxy has been found in the field, as it looked 1 billion years after the big bang.

Image above: This view of a massive cluster of galaxies unveils a very cluttered-looking universe filled with galaxies near and far. Some are distorted like a funhouse mirror through a "space warp" phenomenon first predicted by Einstein a century ago. Image Credits: NASA, ESA, and J. Lotz (STScI).

This frontier image provides a sneak peak of the early universe, and gives us a taste of what the James Webb Space Telescope will be capable of seeing in greater detail when it launches in 2018.

The Frontier Fields program is an ambitious three-year effort, begun in 2013, that teams Hubble with NASA's other Great Observatories - the Spitzer S pace Telescope and the Chandra X-ray Observatory - to probe the early universe by studying large galaxy lusters. Identifying the magnified images of background galaxies within these clusters will help astronomers to improve their models of the distribution of both ordinary and dark matter in the galaxy cluster. This is key to understanding the mysterious nature of dark matter that comprises most of the mass of the universe.

The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA's Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Maryland, conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy in Washington, D.C.

mercredi 20 juillet 2016

Image above: The SpaceX Dragon is captured in the grips of the Canadarm2 robotic arm. Image Credit: NASA TV.

SpaceX/Dragon Arrives at the Space Station

While the International Space Station was traveling 252 statute miles over the Great Lakes, NASA’s Expedition 48 Commander Jeff Williams and NASA Flight Engineer Kate Rubins used the station’s 57.7-foot (17.6-meter) robotic arm to reach out and capture the Dragon spacecraft at 6:56 a.m. EDT.

Dragon Attached to Station’s Harmony Module

Image above: The SpaceX Dragon is seen attached to the International Space Station’s Harmony module just before orbital sunrise. Image Credit: NASA TV.

The SpaceX Dragon cargo spacecraft was bolted into place on the Harmony module of the International Space Station at 10:03 a.m. EDT as the station flew about 252 statute miles over the California and Oregon border.

The spacecraft is delivering nearly 5,000 pounds of science, hardware and supplies, including instruments to perform the first-ever DNA sequencing in space, and the first of two identical international docking adapters (IDA). The IDAs will provide a means for commercial spacecraft to dock to the station in the near future as part of NASA’s Commercial Crew Program.

Dragon is scheduled to depart the space station Aug. 29 when it will return critical science research back to Earth. It is the second cargo spacecraft to arrive on station this week. On Monday, July 18, a Russian ISS Progress 64 cargo craft docked to the Pirs docking compartment of the space station at 8:22 p.m., where it will remain for about six months.

Hatches Between Dragon and the Station are Open

SpaceX Dragon Attached to the Space Station

The hatches between Dragon and station were opened at 2:27 p.m. EDT Wednesday, July 20. The crew entered to document the interior and will begin unloading cargo this afternoon.

The spacecraft delivered nearly 5,000 pounds of science, hardware and supplies, including instruments to perform the first-ever DNA sequencing in space, and the first of two identical international docking adapters (IDA). The IDAs will provide a means for commercial spacecraft to dock to the station in the near future as part of NASA’s Commercial Crew Program.

(Highlights: Week of July 11, 2016) - Crew members on the International Space Station prepared for the arrival of new investigations on the ninth SpaceX resupply mission, scheduled to arrive July 20, which included setting up hardware to receive cells from a human heart.

Spaceflight can cause a variety of health issues with astronauts, which may become more problematic the longer crew members stay in orbit. NASA astronaut Kate Rubins configured the Microgravity Science Glovebox life science hardware to support upcoming operations for the Effects of Microgravity on Stem Cell-Derived Cardiomyocytes (Heart Cells) investigation, which studies the human heart. More specifically, how heart muscle tissue contracts, grows and changes genetically in microgravity and how those changes vary between subjects. Understanding how heart muscle cells, or cardiomyocytes, change in space can improve efforts for studying disease, screening drugs and conducting cell replacement therapy for future space missions.

Animation above: NASA Flight Engineer Kate Rubins performs maintenance and checkout of the Microgravity Science Glovebox on the International Space Station. The glovebox provides a sealed environment for crew members to perform experiments with fluids, flames or fumes. Animation Credit: NASA.

Extended stays aboard the station are becoming more common, and future crews will stay in space for even longer periods as they travel to the moon, asteroids or Mars. Living without gravity’s influence for long periods can cause negative health effects such as muscle atrophy, including potential atrophy of heart muscle. This investigation cultures heart cells on the station for a month to determine those muscle cells change on a cellular and molecular level in space, improving understanding of microgravity’s negative effects. Understanding changes to heart muscle cells benefits cardiovascular research on Earth, where heart disease is a leading cause of death in many countries.

Preparations for SpaceX-9 arrival also continued on ISS as the crew made the habitats ready for a batch of 12 mice to see how the rodents change genetically after exposure to space. The Transcriptome analysis and germ-cell development analysis of mice in the space (Mouse Epigenetics) will study the DNA of mice spending one month in space. Those mice will be returned to JAXA (Japan Aerospace Exploration Agency) where scientists will look for any genetic changes in the offspring of the space-flown mice. Results from this investigation will help define the long-term effects of spaceflight on genetic activity, from changes in gene expression in individual organs to changes in DNA that can be inherited later. Mice are an important model for human health, so the data from this investigation serves as a proxy for understanding how the human body changes in space, and how those changes may affect later generations.

International Space Station (ISS). Image Credit: NASA

Two separate investigations watched developing weather patterns on Earth, one that examined the development of typhoons and hurricanes; and another that looked at the planet's climate in general.

ISS-RapidScat is a space-based scatterometer -- a radar instrument measuring wind speed and direction over the ocean, used for weather forecasting, hurricane monitoring, and observations of large-scale climate phenomena such as El Niño. The ISS-RapidScat instrument enhances measurements from other international scatterometers by crosschecking their data. It measured Super Typhoon Nepartak as it approached Taiwan with wind speeds in excess of 60 mph. ISS-RapidScat also took measurements of Hurricane Blas off the coast of Baja California and another tropical depression that was forming in the same area. The investigation helps take more precise measurements to develop new techniques to predict weather patterns and help communities prepare for strong storms.

Image above: NASA astronaut Jeff Williams captured this photo from the International Space Station of Super Typhoon Nepartak on July 7, 2016. The ISS-RapidScat – a space-based scatterometer attached to the exterior of the station – measured the typhoon’s wind speed and direction as it approached Taiwan with wind speeds in excess of 60 mph. The investigation takes precise measurements that could lead to new techniques to predict weather patterns and help communities prepare for storms. Image Credit: NASA.

The Cloud-Aerosol Transport System (CATS) -- installed on the outside of the space station -- passed a major milestone while observing clouds over Southern Asia. The CATS light detection and ranging system measures the location, composition and distribution of pollution, dust, smoke, aerosols and other particulates in the atmosphere using lasers. While observing India, CATS surpassed 100 billion laser pulses in orbit. A better understanding of cloud and aerosol coverage over a long period will help scientists create a better model of Earth's climate system and predict climate changes more precisely.

Progress was made on other investigations and facilities this week, including SOLAR, Vessel ID System, Dynamic Surf-3, ISS Ham, Gecko Gripper, Radi-N2, Meteor, Manufacturing Device, and 3D Printing in Zero-G.

Image above: This artist's illustration shows two Earth-sized planets, TRAPPIST-1b and TRAPPIST-1c, passing in front of their parent red dwarf star, which is much smaller and cooler than our sun. NASA's & ESA's Hubble Space Telescope looked for signs of atmospheres around these planets. Image Credits: NASA/ESA/STScI/J. de Wit (MIT).

Using Hubble Space Telescope, astronomers have conducted the first search for atmospheres around temperate, Earth-sized planets beyond our solar system and found indications that increase the chances of habitability on two exoplanets.

Specifically, they discovered that the exoplanets TRAPPIST-1b and TRAPPIST-1c, approximately 40 light-years away, are unlikely to have puffy, hydrogen-dominated atmospheres usually found on gaseous worlds.

“The lack of a smothering hydrogen-helium envelope increases the chances for habitability on these planets,” said team member Nikole Lewis of the Space Telescope Science Institute (STScI) in Baltimore. “If they had a significant hydrogen-helium envelope, there is no chance that either one of them could potentially support life because the dense atmosphere would act like a greenhouse.”

Julien de Wit of the Massachusetts Institute of Technology in Cambridge, Massachusetts, led a team of scientists to observe the planets in near-infrared light using Hubble’s Wide Field Camera 3. They used spectroscopy to decode the light and reveal clues to the chemical makeup of an atmosphere. While the content of the atmospheres is unknown and will have to await further observations, the low concentration of hydrogen and helium has scientists excited about the implications.

“These initial Hubble observations are a promising first step in learning more about these nearby worlds, whether they could be rocky like Earth, and whether they could sustain life,” says Geoff Yoder, acting associate administrator for NASA’s Science Mission Directorate in Washington. “This is an exciting time for NASA and exoplanet research.”

The planets orbit a red dwarf star at least 500 million years old, in the constellation of Aquarius. They were discovered in late 2015 through a series of observations by the TRAnsiting Planets and PlanetesImals Small Telescope (TRAPPIST), a Belgian robotic telescope located at ESA’s (European Space Agency’s) La Silla Observatory in Chile.

TRAPPIST-1b completes a circuit around its red dwarf star in 1.5 days and TRAPPIST-1c in 2.4 days. The planets are between 20 and 100 times closer to their star than the Earth is to the sun. Because their star is so much fainter than our sun, researchers think that at least one of the planets, TRAPPIST-1c, may be within the star’s habitable zone, where moderate temperatures could allow for liquid water to pool.

Hubble Makes First Measurements of Earth-Sized Exoplanet Atmospheres

Video above: On May 4, 2016, NASA’s Hubble Space Telescope made the first spectroscopic measurements of two of the three known Earth-sized exoplanets in the TRAPPIST-1 system, just 40 light-years away. Video Credit: NASA.

On May 4, astronomers took advantage of a rare simultaneous transit, when both planets crossed the face of their star within minutes of each other, to measure starlight as it filtered through any existing atmosphere. This double-transit, which occurs only every two years, provided a combined signal that offered simultaneous indicators of the atmospheric characters of the planets.

The researchers hope to use Hubble to conduct follow-up observations to search for thinner atmospheres, composed of elements heavier than hydrogen, like those of Earth and Venus.

“With more data, we could perhaps detect methane or see water features in the atmospheres, which would give us estimates of the depth of the atmospheres,” said Hannah Wakeford, the paper’s second author, at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.

Observations from future telescopes, including NASA’s James Webb Space Telescope, will help determine the full composition of these atmospheres and hunt for potential biosignatures, such as carbon dioxide and ozone, in addition to water vapor and methane. Webb also will analyze a planet’s temperature and surface pressure – key factors in assessing its habitability.

“These Earth-sized planets are the first worlds that astronomers can study in detail with current and planned telescopes to determine whether they are suitable for life,” said de Wit. “Hubble has the facility to play the central atmospheric pre-screening role to tell astronomers which of these Earth-sized planets are prime candidates for more detailed study with the Webb telescope.”

The results of the study appear in the July 20 issue of the journal Nature.

The Hubble Space Telescope is a project of international cooperation between NASA and ESA. Goddard manages the telescope and STScI conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy in Washington.

On our most recent flight, we performed a test to prove the Crew Capsule could safely land with only two of its three parachutes open. On a nominal flight with all three parachutes deployed, the capsule descends at about 16 mph before firing a retrorocket just a few feet above the ground. This retrorocket firing is what creates the large cloud of dust you see just before the capsule lands, and slows the capsule down to 3 mph before it touches the ground. This last bit of speed is absorbed by a ring shaped crushable bumper made of aluminum honeycomb material mounted on the bottom of the capsule. The ring is made of eight segments.

CC during post landing recovery operations

On this last mission, with one chute intentionally failed, the capsule was descending at 23 mph before firing its retrorocket. The retrorocket took out most of that velocity, and the crushable ring did the rest of the job. Below, you can see a couple of pictures of the crushable after the flight test. The first picture shows it mounted under the vehicle after we lifted it off the ground post-flight. The second picture shows a side view of the eight segments after we removed them from the vehicle. Even with one chute out, the crushable barely crushed. When new, the crushable is about 5.5 inches high and can crush down to less than one inch high, providing a constant deceleration force as it crushes. After the mission, the crushable was still over 5 inches high along nearly the entire circumference of the ring.

We’ve designed the capsule to ensure astronaut safety not just for a failure of one parachute, but even for a failure of two parachutes. In addition to the retrorocket system and the crushable ring, there is an energy absorbing mechanism mounted underneath each seat.

The SpaceX Dragon is chasing the International Space Station and the Expedition 48 crew is getting ready for its approach and capture Wednesday morning. This follows Monday evening’s rendezvous and docking of the Progress 64 resupply ship from Roscosmos.

Dragon is delivering several science experiments including a DNA sequencing study and the Heart Cells investigation. The private space freighter is also carrying one of two International Docking Adapters. The adapters will enable future crewed vehicles from Boeing and SpaceX to dock to the space station.

The research, hardware and other supplies stowed inside Dragon total nearly 5,000 pounds. Dragon will be robotically attached to the Harmony module after astronauts Jeff Williams and Kate Rubins capture it with the 57.7 foot long Canadarm2. This will be the second cargo mission to arrive at the station in less than two days.

The Progress arrival Monday night brought more than three tons of food, fuel and supplies for the Expedition 48 crew. Progress automatically docked to the Pirs docking compartment after launching Saturday evening from Kazakhstan.

Russian Resupply Ship Arrives at Space Station

video above: Two days after its launch from the Baikonur Cosmodrome in Kazakhstan, the unpiloted Russian ISS Progress 64 cargo ship automatically docked to the Pirs Docking Compartment on the Russian segment of the International Space Station July 18. The new Progress is delivering three tons of food, fuel and supplies to the six crewmembers comprising the Expedition 48 crew. The Progress will remain attached to the station until late January, when it will undock and commanded to deorbit so it can burn up in the Earth’s atmosphere. Video Credit: NASA.

Williams, Rubins and Flight Engineer Takuya Onishi prepared for the Dragon’s arrival on Tuesday and participated in a variety of research and maintenance activities. The three cosmonauts Oleg Skripochka, Alexey Ovchinin and Anatoly Ivanishin slept in Tuesday after a long day Monday preparing for the Progress delivery.

Two key climate change indicators -- global surface temperatures and Arctic sea ice extent -- have broken numerous records through the first half of 2016, according to NASA analyses of ground-based observations and satellite data.

Each of the first six months of 2016 set a record as the warmest respective month globally in the modern temperature record, which dates to 1880, according to scientists at NASA's Goddard Institute for Space Studies (GISS) in New York. The six-month period from January to June was also the planet's warmest half-year on record, with an average temperature 1.3 degrees Celsius (2.4 degrees Fahrenheit) warmer than the late nineteenth century.

NASA Sees Temperatures Rise and Sea Ice Shrink - Climate Trends 2016

Video above: Each of the first six months of 2016 set a record as the warmest respective month globally in the modern temperature record, which dates to 1880. Meanwhile, five of the first six months set records for the smallest monthly Arctic sea ice extent since consistent satellite records began in 1979.

Five of the first six months of 2016 also set records for the smallest respective monthly Arctic sea ice extent since consistent satellite records began in 1979, according to analyses developed by scientists at NASA's Goddard Space Flight Center, in Greenbelt, Maryland. The one exception, March, recorded the second smallest extent for that month.

While these two key climate indicators have broken records in 2016, NASA scientists said it is more significant that global temperature and Arctic sea ice are continuing their decades-long trends of change. Both trends are ultimately driven by rising concentrations of heat-trapping carbon dioxide and other greenhouse gases in the atmosphere.

The extent of Arctic sea ice at the peak of the summer melt season now typically covers 40 percent less area than it did in the late 1970s and early 1980s. Arctic sea ice extent in September, the seasonal low point in the annual cycle, has been declining at a rate of 13.4 percent per decade.

Image above: Chunks of sea ice, melt ponds and open water are all seen in this image captured at an altitude of 1,500 feet by the NASA's Digital Mapping System instrument during an Operation IceBridge flight over the Chukchi Sea on Saturday, July 16, 2016.Image Credits: NASA/Goddard/Operation IceBridge.

"While the El Niño event in the tropical Pacific this winter gave a boost to global temperatures from October onwards, it is the underlying trend which is producing these record numbers," GISS Director Gavin Schmidt said.

Previous El Niño events have driven temperatures to what were then record levels, such as in 1998. But in 2016, even as the effects of the recent El Niño taper off, global temperatures have risen well beyond those of 18 years ago because of the overall warming that has taken place in that time.

The global trend in rising temperatures is outpaced by the regional warming in the Arctic, said Walt Meier, a sea ice scientist at NASA Goddard.

"It has been a record year so far for global temperatures, but the record high temperatures in the Arctic over the past six months have been even more extreme," Meier said. "This warmth as well as unusual weather patterns have led to the record low sea ice extents so far this year."

NASA tracks temperature and sea ice as part of its effort to understand the Earth as a system and to understand how Earth is changing. In addition to maintaining 19 Earth-observing space missions, NASA also sends researchers around the globe to investigate different facets of the planet at closer range. Right now, NASA researchers are working across the Arctic to better understand both the processes driving increased sea ice melt and the impacts of rising temperatures on Arctic ecosystems.

Graphic above: The first six months of 2016 were the warmest six-month period in NASA's modern temperature record, which dates to 1880. Image Credits: NASA/Goddard Institute for Space Studies.

NASA's long-running Operation IceBridge campaign last week began a series of airborne measurements of melt ponds on the surface of the Arctic sea ice cap. Melt ponds are shallow pools of water that form as ice melts. Their darker surface can absorb more sunlight and accelerate the melting process. IceBridge is flying out of Barrow, Alaska, during sea ice melt season to capture melt pond observations at a scale never before achieved. Recent studies have found that the formation of melt ponds early in the summer is a good predictor of the yearly minimum sea ice extent in September.

"No one has ever, from a remote sensing standpoint, mapped the large-scale depth of melt ponds on sea ice," said Nathan Kurtz, IceBridge’s project scientist and a sea ice researcher at NASA Goddard. "The information we’ll collect is going to show how much water is retained in melt ponds and what kind of topography is needed on the sea ice to constrain them, which will help improve melt pond models."

Operation IceBridge is a NASA airborne mission that has been flying multiple campaigns at both poles each year since 2009, with a goal of maintaining critical continuity of observations of sea ice and the ice sheets of Greenland and Antarctica.

At the same time, NASA researchers began in earnest this year a nearly decade-long, multi-faceted field study of Arctic ecosystems in Alaska and Canada. The Arctic-Boreal Vulnerability Experiment (ABoVE) will study how forests, permafrost and other ecosystems are responding to rising temperatures in the Arctic, where climate change is unfolding faster than anywhere else on the planet.

ABoVE consists of dozens individual experiments that over years will study the region's changing forests, the cycle of carbon movement between the atmosphere and land, thawing permafrost, the relationship between fire and climate change, and more.

Image above: In 2010, NASA's Wide-field Infrared Survey Explorer (WISE) mission observed the entire sky twice. Astronomers used these data to point out the X-shaped structure in the bulge of the Milky Way, contained in the small circle at center, as well as the inset image. The circled central portion covers roughly the area of sky that would be blocked by a basketball when held out at arm’s length. Image Credits: NASA/JPL-Caltech/D.Lang.

A new understanding of our galaxy's structure began in an unlikely way: on Twitter. A research effort sparked by tweets led scientists to confirm that the Milky Way’s central bulge of stars forms an “X” shape. The newly published study uses data from NASA's Wide-field Infrared Survey Explorer (WISE) mission.

The unconventional collaboration started in May 2015 when Dustin Lang, an astronomer at the Dunlap Institute of the University of Toronto, posted galaxy maps to Twitter, using data from WISE's two infrared surveys of the entire sky in 2010. Infrared light allows astronomers to see the structures of galaxies in spite of dust, which blocks crucial details in visible light. Lang was using the WISE data in a project to map the web of galaxies far outside our Milky Way, which he made available through an interactive website.

But it was the Milky Way's appearance in the tweets that got the attention of other astronomers. Some chimed in about the appearance of the bulge, a football-shaped central structure that is three-dimensional compared to the galaxy’s flat disk. Within the bulge, the WISE data seemed to show a surprising X structure, which had never been as clearly demonstrated before in the Milky Way. Melissa Ness, a postdoctoral researcher at the Max Planck Institute for Astronomy in Heidelberg, Germany, recognized the significance of the X shape, and contacted Lang.

The two met a few weeks later at a conference in Michigan, and decided to collaborate on analyzing the bulge using Lang's WISE maps. Their work resulted in a new study published in the Astronomical Journal confirming an X-shaped distribution of stars in the bulge.

"The bulge is a key signature of formation of the Milky Way," said Ness, the study's lead author. "If we understand the bulge we will understand the key processes that have formed and shaped our galaxy."

Image above: To reveal the X shape in the Milky Way’s central bulge, researchers took WISE observations and subtracted a model of how stars would be distributed in a symmetrical bulge. Image Credits: NASA/JPL-Caltech/D.Lang.

The Milky Way is an example of a disk galaxy -- a collection of stars and gas in a rotating disk. In these kinds of galaxies, when the thin disk of gas and stars is sufficiently massive, a “stellar bar” may form, consisting of stars moving in a box-shaped orbit around the center. Our own Milky Way has a bar, as do nearly two-thirds of all nearby disk galaxies.

Over time, the bar may become unstable and buckle in the center. The resulting “bulge” would contain stars that move around the galactic center, perpendicular to the plane of the galaxy, and in and out radially. When viewed from the side, the stars would appear distributed in a box-like or peanut-like shape as they orbit. Within that structure, according to the new study, there is a giant X-shaped structure of stars crossing at the center of the galaxy.

A bulge can also form when galaxies merge, but the Milky Way has not merged with any large galaxy in at least 9 billion years.

"We see the boxy shape, and the X within it, clearly in the WISE image, which demonstrates that internal formation processes have driven the bulge formation," Ness said. "This also reinforces the idea that our galaxy has led a fairly quiet life, without major merging events since the bulge was formed, as this shape would have been disrupted if we had any major interactions with other galaxies."

The Milky Way's X-shaped bulge had been reported in previous studies. Images from the NASA Cosmic Background Explorer (COBE) satellite's Diffuse Infrared Background Experiment suggested a boxy structure for the bulge. In 2013, scientists at the Max Planck Institute for Extraterrestrial Physics published 3-D maps of the Milky Way that also included an X-shaped bulge, but these studies did not show an actual image of the X shape. Ness and Lang's study uses infrared data to show the clearest indication yet of the X shape.

Additional research is ongoing to analyze the dynamics and properties of the stars in the Milky Way's bulge.

Collaborating on this study was unusual for Lang -- his expertise is in using computer science to understand large-scale astronomical phenomena, not the dynamics and structure of the Milky Way. But he was able to enter a new field of research because he posted maps to social media and used openly accessible WISE data.

"To me, this study is an example of the interesting, serendipitous science that can come from large data sets that are publicly available," he said. "I'm very pleased to see my WISE sky maps being used to answer questions that I didn't even know existed."

NASA's Jet Propulsion Laboratory, Pasadena, California, manages and operates WISE for NASA's Science Mission Directorate in Washington. The spacecraft was put into hibernation mode in 2011, after it scanned the entire sky twice, thereby completing its main objectives. In September 2013, WISE was reactivated, renamed NEOWISE and assigned a new mission to assist NASA's efforts to identify potentially hazardous near-Earth objects.

lundi 18 juillet 2016

Using observations from ESA's Venus Express satellite, scientists have shown for the first time how weather patterns seen in Venus' thick cloud layers are directly linked to the topography of the surface below. Rather than acting as a barrier to our observations, Venus' clouds may offer insight into what lies beneath.

Gravity waves on Venus. Image Credit: ESA

Venus is famously hot, due to an extreme greenhouse effect which heats its surface to temperatures as high as 450 degrees Celsius. The climate at the surface is oppressive; as well as being hot, the surface environment is dimly lit, due to a thick blanket of cloud which completely envelops the planet. Ground-level winds are slow, pushing their way across the planet at painstaking speeds of about 1 metre per second – no faster than a gentle stroll.

However, that is not what we see when we observe our sister planet from above. Instead, we spy a smooth, bright covering of cloud. This cloud forms a 20-km-thick layer that sits between 50 and 70 km above the surface and is thus far colder than below, with typical temperatures of about -70 degrees Celsius – similar to temperatures found at the cloud-tops of Earth. The upper cloud layer also hosts more extreme weather, with winds that blow hundreds of times faster than those on the surface (and faster than Venus itself rotates, a phenomenon dubbed 'super-rotation').

While these clouds have traditionally blocked our view of Venus' surface, meaning we can only peer beneath using radar or infrared light, they may actually hold the key to exploring some of Venus' secrets. Scientists suspected the weather patterns rippling across the cloud-tops to be influenced by the topography of the terrain below. They have found hints of this in the past, but did not have a complete picture of how this may work – until now.

Scientists using observations from ESA's Venus Express satellite have now greatly improved our climate map of Venus by exploring three aspects of the planet's cloudy weather: how quickly winds on Venus circulate, how much water is locked up within the clouds, and how bright these clouds are across the spectrum (specifically in ultraviolet light).

Venus cloud tops. Credit: ESA/MPS/DLR/IDA

"Our results showed that all of these aspects – the winds, the water content, and the cloud composition – are somehow connected to the properties of Venus' surface itself," says Jean-Loup Bertaux of LATMOS (Laboratoire Atmosphères, Milieux, Observations Spatiales) near Versailles, France, and lead author of the new Venus Express study. "We used observations from Venus Express spanning a period of six years, from 2006 to 2012, which allowed us to study the planet's longer-term weather patterns."

Although Venus is very dry by Earth standards, its atmosphere does contain some water in the form of vapour, particularly beneath its cloud layer. Bertaux and colleagues studied Venus' cloud-tops in the infrared part of the spectrum, allowing them to pick up on the absorption of sunlight by water vapour and detect how much was present in each location at cloud-top level (70 km altitude).

They found one particular area of cloud, near Venus' equator, to be hoarding more water vapour than its surroundings. This 'damp' region was located just above a 4500-metre-altitude mountain range named Aphrodite Terra. This phenomenon appears to be caused by water-rich air from the lower atmosphere being forced upwards above the Aphrodite Terra mountains, leading researchers to nickname this feature the 'fountain of Aphrodite'.

"This 'fountain' was locked up within a swirl of clouds that were flowing downstream, moving from east to west across Venus," says co-author Wojciech Markiewicz of the Max-Planck Institute for Solar System Research in Göttingen, Germany. "Our first question was, 'Why?' Why is all this water locked up in this one spot?"

In parallel, the scientists used Venus Express to observe the clouds in ultraviolet light, and to track their speeds. They found the clouds downstream of the 'fountain' to reflect less ultraviolet light than elsewhere, and the winds above the mountainous Aphrodite Terra region to be some 18 per cent slower than in surrounding regions.

All three of these factors can be explained by one single mechanism caused by Venus' thick atmosphere, propose Bertaux and colleagues.

"When winds push their way slowly across the mountainous slopes on the surface they generate something known as gravity waves," adds Bertaux. "Despite the name, these have nothing to do with gravitational waves, which are ripples in space-time – instead, gravity waves are an atmospheric phenomenon we often see in mountainous parts of Earth's surface. Crudely speaking, they form when air ripples over bumpy surfaces. The waves then propagate vertically upwards, growing larger and larger in amplitude until they break just below the cloud-top, like sea waves on a shoreline."

As the waves break, they push back against the fast-moving high-altitude winds and slow them down, meaning that winds above Venus' Aphrodite highlands are persistently slower than elsewhere.

However, these winds re-accelerate to their usual speeds downstream of Aphrodite Terra – and this motion acts as an air pump. The wind circulation creates an upwards motion in Venus' atmosphere that carries water-rich air and ultraviolet-dark material up from below the cloud-tops, bringing it to the surface of the cloud layer and creating both the observed 'fountain' and an extended downwind plume of vapour.

Venus Express spacecraft. Image Credit: ESA

"We've known for decades that Venus' atmosphere contains a mysterious ultraviolet absorber, but we still don't know its identity," says Bertaux. "This finding helps us understand a bit more about it and its behaviour – for example, that it's produced beneath the cloud-tops, and that ultraviolet-dark material is forced upwards through Venus' cloud-tops by wind circulation."

Scientists already suspected that there were ascending motions in Venus' atmosphere all along the equator, caused by the higher levels of solar heating. This finding reveals that the amount of water and ultraviolet-dark material found in Venus' clouds is also strongly enhanced at particular places around the planet's equator. "This is caused by the mountains way down on Venus' surface, which trigger rising waves and circulating winds that dredge up material from below," says Markiewicz.

As well as helping us understand more about Venus, the finding that surface topography can significantly affect atmospheric circulation has consequences for our understanding of planetary super-rotation, and of climate in general.

"This certainly challenges our current General Circulation Models," says Håkan Svedhem, ESA Project Scientist for Venus Express. "While our models do acknowledge a connection between topography and climate, they don't usually produce persistent weather patterns connected to topographical surface features. This is the first time that this connection has been shown clearly on Venus – it's a major result."

Venus Express was in operation at Venus from 2006 until 2014, when its mission concluded and the spacecraft began its descent through Venus' atmosphere.

The study by Bertaux and colleagues made use of several years of Venus Express observations gathered by the Venus Monitoring Camera (VMC) – to explore the wind speeds and ultraviolet brightness of the clouds – and by the SPICAV spectrometer (Spectroscopy for Investigation of Characteristics of the Atmosphere of Venus) – to study the amount of water vapour contained within the clouds.

"This research wouldn't have been possible without Venus Express' reliable and long-term monitoring of the planet across multiple parts of the spectrum. The data used in this study were collected over many years," adds Svedhem. "Crucially, knowing more about Venus' circulation patterns may help us to constrain the identity of the planet's mysterious ultraviolet absorber, so we can understand more about the planet's atmosphere and climate as a whole."

The study is based on data from Venus Express' VMC (Venus Monitoring Camera) and SPICAV spectrometer (Spectroscopy for Investigation of Characteristics of the Atmosphere of Venus).

ESA's Venus Express was launched in 2005, arrived at Venus in 2006, and spent eight years exploring the planet from orbit. The mission ended in December 2014 after the spacecraft ran out of orbit-raising propellant and entered the atmosphere. Some science highlights from Venus Express can be found here: http://sci.esa.int/venus-express/54062-1-shape-shifting-polar-vortices/

An international team of astronomers has discovered and confirmed a treasure trove of new worlds using NASA’s Kepler spacecraft on its K2 mission. Among the findings tallying 197 initial planet candidates, scientists have confirmed 104 planets outside our solar system. Among the confirmed is a planetary system comprising four promising planets that could be rocky.

The planets, all between 20 and 50 percent larger than Earth by diameter, are orbiting the M dwarf star K2-72, found 181 light years away in the direction of the Aquarius constellation. The host star is less than half the size of the sun and less bright. The planets’ orbital periods range from five and a half to 24 days, and two of them may experience irradiation levels from their star comparable to those on Earth. Despite their tight orbits — closer than Mercury's orbit around the sun — the possibility that life could arise on a planet around such a star cannot be ruled out, according to lead author Crossfield, a Sagan Fellow at the University of Arizona's Lunar and Planetary Laboratory.

The researchers achieved this extraordinary "roundup" of exoplanets by combining data with follow-up observations by earth-based telescopes including the North Gemini telescope and the W. M. Keck Observatory in Hawaii, the Automated Planet Finder of the University of California Observatories, and the Large Binocular Telescope operated by the University of Arizona. The discoveries are published online in the Astrophysical Journal Supplement Series.

Image above: Artist concept. A crop of more than 100 planets, discovered by NASA’s Kepler Space Telescope, includes four in Earth’s size-range orbiting a single dwarf star. Two of these planets are too hot to support life as we know it, but two are in the star’s “habitable” zone, where liquid water could exist on the surface. These small, rocky worlds are far closer to their star than Mercury is to our sun. But because the star is smaller and cooler than ours, its habitable zone is much closer. One of the two planets in the habitable zone, K2-72c, has a “year” about 15 Earth-days long—the time it takes to complete one orbit. This closer planet is likely about 10% warmer than Earth. On the second, K2-72e, a year lasts 24 Earth days, this slightly more distant planet would be about 6% colder than Earth. Image Credits: NASA/JPL.

Both Kepler and its K2 mission discover new planets by measuring the subtle dip in a star's brightness caused by a planet passing in front of its star. In its initial mission, Kepler surveyed just one patch of sky in the northern hemisphere, determining the frequency of planets whose size and temperature might be similar to Earth orbiting stars similar to our sun. In the spacecraft’s extended mission in 2013, it lost its ability to precisely stare at its original target area, but a brilliant fix created a second life for the telescope that is proving scientifically fruitful.

After the fix, Kepler started its K2 mission, which has provided an ecliptic field of view with greater opportunities for Earth-based observatories in both the northern and southern hemispheres. Additionally, the K2 mission is entirely community-driven with all targets proposed by the scientific community.

Because it covers more of the sky, the K2 mission is capable of observing a larger fraction of cooler, smaller, red-dwarf type stars, and because such stars are much more common in the Milky Way than sun-like stars, nearby stars will predominantly be red dwarfs.

"An analogy would be to say that Kepler performed a demographic study, while the K2 mission focuses on the bright and nearby stars with different types of planets," said Ian Crossfield. “The K2 mission allows us to increase the number of small, red stars by a factor of 20, significantly increasing the number of astronomical 'movie stars' that make the best systems for further study."

To validate candidate planets identified by K2, the researchers obtained high-resolution images of the planet-hosting stars as well as high-resolution optical spectroscopy. By dispersing the starlight as through a prism, the spectrographs allowed the researchers to infer the physical properties of a star — such as mass, radius and temperature — from which the properties of any planets orbiting it can be inferred.

These observations represent a natural stepping stone from the K2 mission to NASA's other upcoming exoplanet missions such as the Transiting Exoplanet Survey Satellite and James Webb Space Telescope.

"This bountiful list of validated exoplanets from the K2 mission highlights the fact that the targeted examination of bright stars and nearby stars along the ecliptic is providing many interesting new planets,” said Steve Howell, project scientist for the K2 mission at NASA’s Ames Research Center in Moffett Field, California. "These targets allow the astronomical community ease of follow-up and characterization, providing a few gems for first study by the James Webb Space Telescope, which could perhaps tell us about the planets’ atmospheres."

This work was performed in part under contract with the Jet Propulsion Laboratory (JPL) funded by NASA through the Sagan Fellowship Program executed by the NASA Exoplanet Science Institute.

NASA Ames manages the Kepler and K2 missions for NASA's Science Mission Directorate. NASA's Jet Propulsion Laboratory in Pasadena, California, managed Kepler mission development. Ball Aerospace & Technologies Corporation operates the flight system with support from the Laboratory for Atmospheric and Space Physics at the University of Colorado at Boulder.